package main

import (
	"flag"
	"fmt"
	"strings"
)

var n = flag.Bool("n", false, "omit trailing newline") //bool类型，默认换行，想不换行就加-n
var sep = flag.String("s", " ", "separator")           //string类型，默认空格，想换成其他字符就加-s，再加自定义字符

func main() {
	flag.Parse()
	fmt.Print(strings.Join(flag.Args(), *sep))
	if !*n {
		fmt.Println()
	}
}
